I have been put on this beta blocker due to heart palpitations. Since taking this medication, I am more anxious, my hands shake, I have a headache, I feel like I could run a marathon, BUT yet I am tired and my heart has not stopped palpitating. Is this something serious? Should I wait these effects out? Is this a "normal" bodily reaction? I am 36 and I am taking 12.5mg once a day. I want my palpitations to stop, but not at this expense of my body.